UPDATE 8/30: Today, we have released Windows 10 Insider Preview Build 17744 (RS5) + KB4459375 to Windows Insiders in the Slow ring.
KB4459375 includes a single fix for the issue causing PCs to bugcheck (BSOD) when logging out of your user profile or shutting down your PC.
KB4459375 is packaged using a new design that Windows Insiders preview builds can download and install more efficiently.
To learn more, see What’s next for Windows 10 and Windows Server quality updates.